Joss Stone?
Nicely done. Does she act? She does have that earthy timbre and she can really swing.
Doesn’t really sound too much like Janis, to me, but she could do it. Somehow I doubt she’d be interested, what with her music career, but you never know.
Diana Fuchs sounds right, and Pink may be able to pull it off. Juliet Simms’ voice didn’t have enough grit for me.
None of these are who I was thinking of, but all are in the ballpark for what’s required. I’ve never heard Amy Adams sing, but I really hope she has the chops if they’re going to have her do all of the vocals herself. Janis’ voice is very special to me and the wrong sound would take me out of the movie quicker and more often than any 555 number.
Is Bonnie Tyler still around? j/k
Crystal Bowersox
I came here to post exactly the same thing.
I love Amy Adams, but Joplin seems a stretch for her.
Another vote here. She can play some guitar and lead a band too. I don’t hear any problem with the Janis voice, she can growl with the best.
Vocal chops. Janis Joplin. Pick one.